Method of manufacturing a semiconductor wafer

Abstract

Disclosed is a method of manufacturing a semiconductor wafer. In the present invention, a nucleation site is formed in a region deep into the wafer through low-temperature annealing process, and oxygen or precipitation material, the metallic impurity, or the like is trapped in the nucleation site through rapid thermal annealing process. As a gettering effect is improved using the rapid thermal annealing process, the concentration of the impurity on the surface of the wafer can be lowered and the reliability of the device could be improved. Further, the annealing steps can be reduced than the prior art and the productivity of the device can thus be increased.

1. A method of manufacturing a semiconductor wafer, comprising the steps of:
 annealing a wafer at a low temperature under nitrogen (N 2 ) atmosphere in order to form a nucleation site at a region deep into the wafer; and  
 performing a rapid thermal annealing process under nitrogen (N 2 ) atmosphere after forming the nucleation site so that oxygen precipitation material or metallic impurity is trapped in the nucleation site.  
 
   
   
     2. The method as claimed in  claim 1 , wherein the low-temperature annealing process is performed at a temperature of 650˜850° C. 3˜10 hours. 
   
   
     3. The method as claimed in  claim 1 , wherein the rapid thermal annealing process is performed at a temperature of 1000˜1200° C. for 10 seconds˜5 minutes. 
   
   
     4. The method as claimed in  claim 1 , wherein in the rapid thermal annealing process, a step-up rate is 30˜200° C./sec, a cooling rate is 200˜100° C./sec and the flux of nitrogen (N 2 ) is 1˜20 slpm. 
   
   
     5. The method as claimed in  claim 1 , further comprising the step of before the low-temperature annealing process is implemented, performing high-temperature annealing process in order to diffuse oxygen existing on the surface of the wafer toward the outside. 
   
   
     6. The method as claimed in  claim 5 , wherein the high-temperature annealing process is performed at a temperature of 1000˜1200° C. under dry oxygen (O 2 ) atmosphere for 1˜2 hours.